Any Free or Open Source Software (FOSS) for fluid flow simulation in porous media?

The simulators I know are either not maintained, at a very early stage of development, or written in old programming languages, namely:

* BOAST, UTCHEM, etc. written in Fortran 77 -- http://www.netl.doe.gov/technologies/oil-gas/software/simulat.html
* DuMuX written on top of a C++ library -- http://www.dumux.org/

If you know any alternative, please share.

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UPDATE:

* MRST is a MATLAB® toolbox that is also part of the OPM initiative -- http://www.sintef.no/MRST

* OPM is the best choice if you're a C++ programmer working in the field. Please invest time using it and contribute with code whenever possible -- http://www.opm-project.org